1. Field of the Invention
The present invention relates to a still video camera and, more particularly, to an apparatus for reproducing data signals recorded with a picture signal in the form of a multiplex recording signal.
2. Description of Related Art
A typical conventional still video camera has heretofore been arranged such that the image of an object is photoelectrically converted by means of an image pickup device to capture the object image in the form of a luminance signal (Y) and a color signal (C). These signals are frequency modulated together and recorded on a magnetic disc in the form of a multiplex picture signal. According to a recent unified standard for still video cameras, a data signal which indicates whether a particular record is a field record or frame record and which also carries other information, for example, the ordinal number of a track on which a particular record has been stored, is recorded on a magnetic disc while being superposed upon the above-described picture signal by a frequency multiplexing method.
To modulate the data signal, DPSK (Differential Phase Shift Keying) modulation is adopted. Accordingly, the data signal is subjected to DPSK modulation and recorded on a magnetic disc while being superposed upon the picture signal. To reproduce the recorded data, the data signal is extracted from the frequency-modulated signal that is read out from the magnetic disc and subjected to DPSK demodulation, after waveform shaping. Various apparatuses for reproducing the data signal have been developed [for example, Japanese Patent Application Laid-Open (KOKAI) No. 62-223855 (1987)].
However, conventional data signal reproducing circuits have a complicated circuit configuration, and the scale of the circuit is large. Accordingly, the production cost is high, and the circuit control is complicated.